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So, you need to get ahold of me, eh? Feel free to contact me by email. My service provider is gmail and the username is “mikesmods.com”. That’s m*.com at g*.com. Figure that one out, spambots and email scrape engines! You may also leave a relevant comment on most or all pages of this site. With few exceptions, I typically respond to every comment posted, so go comment-crazy.

Note that I personally moderate every new comment. If your comment does not immediately show up, it is likely because it is being held for moderation. I do this to allow you wonderful people to comment without the agony of signing up or filling in CAPTCHAs (because like you, I hate having to do that too), but also so that the many tens of thousands of spam messages I receive each month do not make it out to the site. Please be patient if your first comment does not appear immediately, I typically will get to it in less than a day or two. Additionally, if you continue to use the same username and email address after a comment has been approved, you are free to comment without further moderation.

And one further note. I try to move all comments posted to this page to the appropriate project page, if I can figure out which project they’re referring to. I’m not deleting them, they’re just somewhere else, I promise!

The original full-featured version of my iPad controller will allow this, but two issues stand in the way of me sending one to you: first, I’ve been intending to re-design it to decrease cost and fix some errors, and I haven’t done that yet, and second, I haven’t written the software to enable backlight control via PC yet. The hardware will do it, but I’m new to the ARM Cortex M0+ platform so I need to learn how to write USB-enabled firmware first. I may not have a working solution for a month or two. As much as I hate to turn folks away, I don’t have an immediate solution for you, sorry! But check back sometime, it’s on the schedule.

Hello, you planning to sell some kit, I have no way to make the pcb so small and I would love to use a lcd retina. Congratulations on your great work. Sorry for my English, is the translator of google. Best regards.

Yes, my boards are simple passthroughs of the DisplayPort signal, and I’m driving them from the regular DisplayPort output of a PC video card (either a Quadro 3800 or a Radeon HD 7870 depending on the location in the house where I’m working). Both of these cards have native DisplayPort outputs, and I have not yet bothered to try and use a converter (not that I know of any x-to-DisplayPort converters capable of the resolution of the Macbook anyway). The OS is Windows 7, as can be seen from most of the photos.

Mike, if I use the mDP output on my MacBook, would there be limitations on the output resolution from my MacBook? I ordered the ipad3 board and BOM , I’m hoping my MacBook Pro will support the retina ipad3 resolution.
Thanks,
Lou

I would be very surprised if your MacBook would not run the panel at native resolution (2048×1536, 3.1 Mpixel). They were (in the past) at least capable of driving Apple’s own 27″ Cinema Display at 2560×1440 (3.7 Mpixel), so the hardware should have more than sufficient power.

You should also be able to run at much lower resolutions, utilizing the GPU’s scaler. But what’s the point of that?

Well, you’re pretty much my hero… You achieve what I dream of. Looking to establish a dialog with you. I picture myself as a distant kinsman with similar ideas floating in my head without the skills ‘You’ve’ achieved. I currently work for AT&T in their data centers, was in the Navy with (at one time) component level electronics skills, and also owned and operated a (high end for the time) computer store in San Diego for 6 years before the AT&T gig. I branched into some minor prototyping but didn’t get to commercial realization before AT&T job closed that chapter in my life. So hopefully you could send me an e-mail back at arakess@yahoo.com and we could correspond a bit. Did you get the iPad digitizer up and functioning too?

P.S.
This is where I ended up before I found your WEB site. See links below: (this is not SPAM or advertising, just links to what I was looking at before I found your creations).

How can I get the kit you spent all that time researching and testing for the macbook pro retina display? I would really like to either make one or buy the kit from you if you sell them… Can you please let me know what all I need to have this all made?

Hi,
Can the board be modified — add-on board — to function as:
“Multi-display architecture using single video controller, US patent #20040222941″. http://www.google.com/patents/US20040222941
Also, will ARM HTPC software run on the chip?
–Eddie P.

Due to the full interoperability between DisplayPort and eDP, this approach is perfectly adaptable to most or all eDP-type displays. All you should need to do is change the output connector for whatever comes on the new panel, and maybe tweak the backlight driver and power supplies to match the requirements of the panel if they’re different from the ones I’ve built. Easy! Drop me a line if you have any specific questions.

Which version are you interested in? Presumably the tiny simple one, since you’re working on a projector build? Actually it’s a moot point, the iPad Mini 2 uses a different LCD connector than the normal iPad 3/4 panel featured here, so the board isn’t compatible!

I don’t have the datasheet for the iPad Mini 2 LCD (LG LP079QX1-SP0V), nor do I have one of the panels, so I’m afraid I can’t do much for you at the moment. Sorry!

It seems to me that it won’t work directly, but maybe it can be modified to work. The panels are pretty similar, the biggest difference seems to be that the mini panel has 6 backlight strings instead of 12 and the connector is 32-pin rather than 51-pin.

I would be very interested in a board which can drive the mini panel. The bigger panel is just a little too large for my project. I would prefer that the board would do the backlight as well, not just the signaling.

Hmm. Well, I hadn’t really considered building any more. The components to build one more would cost more than what I’d want to sell it for, considering the 3-piece minimum order for the PCBs… I don’t think I have any more from the last (first) batch. I’ll double-check that, I’m not sure what happened to the last one.

Otherwise, all the Gerbers and schematics are posted, you could easily order the parts and build one yourself

I saw you mention in a post on Hackaday forum (http://forums.hackaday.com/viewtopic.php?f=4&t=3980#p16920) that a universal lvds converter board might be possible using an FPGA. I know nothing about FPGAs other than a couple of quick tutorials I read. Do you know if it would be possible to detect the pin configuration of the lvds panel via software and use that configuration info to program the FPGA? I just hate the idea that there are all these perfectly good lvds displays out there that go into landfill or recycling when we could reuse them more easily if we had an easy to set up board. (VS having to match up pin configurations manually to a converter.)

Maybe… to a point. You should be able to determine which pins of a given array of pins are the LVDS and clock pairs, because they’ll typically be terminated in the panel with 100 ohms. Figuring out the number of such pairs will tell you whether it uses 6 or 8 bits per pixel. Determining continuity between pins could be done, and measuring capacitance between banks of pins may net you the location of the power pins. There are plenty of tricks you can employ to determine secrets about a circuit in this way.

There are a few things which are impossible to figure out without a little bit more knowledge about the circuit, though. Although you may be able to determine which pins are LVDS, you won’t be able to determine (by examining the black-box circuit alone) which lane is which. You also won’t be able to determine bit ordering within those lanes (JEIDA or VESA), or the necessary timings or native resolution. And you won’t know the operating voltage of the panel.

The backlight is another problem. While you may be able to generalize the particulars of different backlight pinouts, determining the pinout and operating voltage is going to be a real challenge.

But all of this is secondary to the biggest problem: Every panel has a different connector. A truly universal, plug-in-whatever-you’ve-got board would either need bunches of connectors for all possible pin arrangements, or you’d need to adopt a generic pinout and modify each panel’s existing connector to fit. And if you’re going to do that, you can do a little bit of detective work and save a whole lot of effort in the FPGA – or in fact, you no longer need a FPGA at all, and can use an off the shelf controller. And at this point, what you have is one of the myriad $30 eBay LCD controller boards.

My Hackaday post (actually this one is the one mentioning a FPGA) was mostly aimed at what to do if you wanted to have a truly ‘anything’ to ‘anything’ display controller… {VGA, LVDS, HDMI, DisplayPort, DVI, SPI, parallel} to {LVDS, V-by-One, miniLVDS, TTL, TMDS, embedded DisplayPort, SPI} or some such. And as I pointed out in that post, it still involves wiring up every desired connector pinout.

Many or even most common LCD panels’ datasheets are out there (or with simple examination of the LCD’s control board they can be quickly reverse-engineered), so there’s not a huge amount of necessity to do auto-detection of pinouts. Just figure out the pinout and wire it appropriately to a universal LCD controller. Whether you do autodetection or not, you still need to program in the timings and resolution. Ultimately full autodetection of an arbitrary LCD panel is probably impossible even using an FPGA. Sorry for rambling

Sent you an email, didnt get an answer, youre probably busy so I will leave a comment here. I m trying to drive a ipad retina from the edp port of a motherboard (asus q87t). I can understand and design the required cable to interface these two but dont understand the LED requirements. The lcd has more cathode inputs than the motherboard edp port provides, I dont know what to do. Is it possible to connect all the cathodes together and anodes together and wire them together, like regular LEDs or is this a stupid idea? Also, the motherboard gives out 12V or 19V as backlight power, would that be enough to drive the retina display? Thanks.

Sorry about that. I’ve sent you some emails, but I’ll respond here too in case anyone else is curious. To my knowledge, Q87t doesn’t have an onboard LED driver, just an LED control output. You’ll want to implement your own proper PWM backlight driver to drive the LEDs.

It’s generally a bad idea to just connect all the anodes and cathodes together; unless you’re very cautious with how you drive them, some of the LED strings will tend to draw more current than others and you may damage them. If you want to use a DC voltage to test the backlight before designing the driver, you can, but use a current limiting resistor in series with each string to balance the current more accurately between them.

You can use either 12V or 19V, and each has its differences. Using a standard boost driver, you’ll want 12V, because the string voltage is approximately 19V and you can’t boost 19V to 19V. On the other hand, if you use a low-side PWM controller without a built-in boost, you can make direct use of the 19V rail, which saves a bit of circuit complexity. This is all pretty vague information because there’s a lot of variables involved, let me know if you need anything more specific.

Does the display announce itself to the PC? If you attach a second monitor, can you see the panel it in your display properties page? That will at least let you know if your panel is properly powered and your AUX channel is connected and working.

Sorry for the late reply again, yes, the EDID is picked up in Windows with information about resolution, model number etc. Windows even sees it as the second display but output is blank. On the display I just get backlight.

Hmm. So AUX is working but the data lanes aren’t running. Are you sure your DP lane ordering / pinout is correct? I’ve had problems where I had things pinned backward, where AUX works but nothing else does.

You did account for the fact that DisplayPort cables are crossovers, yes?

Hi, Mike!
Hi, engineers!
We’ve implemented ipad3lcd board here using the project documentation, you provided,
that was quite a serious manufacturing challenge and lots of fun
even some carbide 0.3mm bits has been broken and punched out of 1.5mm deep boardhttp://bit.ly/1NYxkzM
I’ve found some random info on how hdmi and dp standards work.
However there may be a place where some consistent knowledge is documented, please tell me,
how to convert the hdmi stream to the display port, which are limitations on hdmi devices if differs.
I would like to thank you, Mike, for your insight and great projects being documented.
That’s awesome, please keep on hacking.

Nice work! I too have broken many bits in my time… standard drill press chucks aren’t centered well enough to cut those teeny tiny holes, I found after the first few. I’ve gotten out of the handmade boards as of the last few years though, it’s just so darn convenient to order professionally-made boards!

Converting HDMI to DisplayPort is no easy task. “Compatible” HDMI, that is, HDMI which follows the DVI data format and not the more modern compressed and encrypted addons, is fairly straightforward – three data pairs, one for each color, and a clock pair carry the pixel data in a “raw” format – basically, the intensity of each color represented as an 8-bit value, encoded as 8b/10b for transmission.

DisplayPort, on the other hand, is actually more like PCI Express than HDMI. It converts the video information into data packets, which it sends sequentially across up to four data lanes. Whereas DVI-compatible HDMI sends raw data on color-specific wire pairs, DisplayPort sends data on all colors on all lanes, and can operate with two or even just a single lane connected. Between display frames, the data lanes also carry auxiliary data such as audio. The data rates on these lanes are quite high, starting at 1.62Gbps and going up to 8.1Gbps as of the most recent standard.

It is simple to convert DisplayPort TO HDMI, because there are many cheap conversion ICs which supply the “active converter dongle” market. But there are comparatively few solutions that go the other way. DisplayPort isn’t nearly as common as HDMI/DVI in the display market, and most displays that are DP compatible also have at least one HDMI/DVI port as well. There are at least one or two conversion ICs out there, but they tend to be difficult to get ahold of in hobbyist quantities. So usually in the hobbyist realm, x-to-DP conversion is handled by a FPGA. There are at least a couple of DisplayPort source cores for FPGA out there, if you search around… I can’t comment any further though, as I haven’t experimented with them.

LQ156D1JX01 and in my case “02″ (same panel really according to d/sheet)

Do you have any hints/ideas for IGZO projector,
or how would I go about fabbing/ (I’m not too electrically inclined so far/atm, FPGA’s ASIC etc) but would be exciting (to know) if I can convert the 4lane Edp input to a say, desktop VGA-out. Is this IGZO model eDP 1.3?

And perhaps in the future (or now if worthwhile) would DIY projector it.. Not sure how anisotropy/contrast, or even how many nitts I’d end up w/ though, so would love thoughts on this.. Or what the end-product could look like. Of course there are various way to diy a projector, but little recently has been done… Thought on implementations/particular caveats one might pursue would be.. uh, cherished.
Havn’t seen any IGZO panels thus-far used in projection; looking for ideas there.

Thanks if it there are any conceivable, viable ways to run this panel to a Desktop (HPC/MAD/VR home-machine)

Want pixel densities to be as high(or bett)/er as are currently on the market.. Also ‘saves’ the worries and/or expense at the moment while waiting for HDR/Quantum dot solutions, et al in the projection world to graduate to higher-end and/or gamut in the mainstream..
Quite a fair bit/lot should settle down over the next year or two. Potentially still even three (according conglomerate release-schedules).
How would one run display to D-VGA/want to do so if could be contrived; custom pcb/circuit isn’t out of the question? Interested in HPC-use along with MadVR….. W/ VP9/HEVC proper FFunc decode..
I’d consider anything to recycle this display.

It would BE VERY NEAT, to mill an opening in bottom of NX500 chassis and swap the panel to my desktop, – WHENEVER, for the time being [thru diy adaptor-solution].

Whoa, there’s a lot of interesting thoughts going on here! I unfortunately don’t yet have enough information on the LQ156D1JX01 and its standalone operation to answer your specific questions. I will say that VGA to DP is about as abstract as it gets, it is more difficult even than HDMI/DVI to DP as you need to first digitize the analog signal before you can begin to manipulate it as necessary. I don’t know of any (easily-accessible) silicon that does this kind of resolution, so you’re probably looking at a hefty FPGA to do the conversion. Then it gets into “is this economically feasible” which is why I haven’t directly pursued such a solution already… I enjoy blowing money on silly projects, but this would be a pretty serious one

Hello Mike, has broken me connector motherboard cable my camera isight on a macbook pro A1278 early 2011. I bought a cable to weld the old and need know the corresponding colors (pinout) since I want to take advantage of the new cable connector.